There is likely no single answer to what causes Parkinson’s

June 8, 2010

HANCOCK - About 50,000 Americans are diagnosed with Parkinson's disease each year. However, researchers are making inroads toward better understanding the disease.

The neurological disease is characterized by a shortage of dopamine, a chemical that helps coordinate body movements. Early non-motor signs include a reduced sense of smell and sleep disorders, according to the National Parkinson's Foundation.

While researchers understand the changes going on in the brain as the result of Parkinson's, the causes are a bit more elusive, said Christian Dinsmore, a neurologist at Portage Health. Genetics are part of it, but there may also be an environmental component as well.

"The probability is there isn't going to be a single answer to what causes Parkinson's," he said.

On average, sufferers are slightly more likely to be male. Most of them are in their 60s or older; only 5 percent of patients are diagnosed before 50.

Usually, Parkinson's manifests itself as a tremor, with two-thirds of patients having them in their upper extremities.

"We often see complaints related to a certain sense of stiffness they have, some incoordination in their upper extremities or some difficulty with walking," Dinsmore said.

Many of the most disabling features that develop over time are mood- and cognition-related, such as depression or dementia, Dinsmore said.

"When I'm seeing patients for the first time, it's useful highlighting that this is more than just a motor disease," he said.

The disease worsens with time. Aside from that, Dinsmore said, it's difficult to set a timeframe.

"Someone who has other medical problems, we expect their disease might be a little more rapid," he said.

A variety of treatments are available, though they primarily relieve the symptoms. Dinsmore made the comparison to pneumonia, where a cough suppressant acts as a symptomatic therapy, while an antibiotic treats the disease.

The "Holy Grail" of Parkinson's research, Dinsmore said, is finding something that functions like that antibiotic.

The existing medications, including levodopa, are primarily used to replenish the brain's supply of dopamine.

"With the medications, you're providing more stimulation in those areas that have been affected by the disease," he said. "You're kind of using medications to make up for a decline in the activity of those systems."